The present disclosure relates to metal organic frameworks. Methods for making the frameworks and methods for removing contaminants from water using the frameworks are also disclosed.
According to the World Health Organization, pharmaceutical contamination of drinking water is an emerging problem. By some estimates, almost 25% of the world's rivers and lakes are contaminated. Although current contaminant levels are generally below therapeutic thresholds, the effects of prolonged exposure at low dosages are unknown. Pharmaceutical contamination could potentially affect aquatic life in addition to humans.
Some drugs (e.g., tetracycline, ciprofloxacin, and 17α-ethynylestradiol) are not easily degraded via conventional water treatment methods. For example, reverse osmosis and membrane filtration may not remove parts per million (ppm) levels of contaminants. The European Union recently finished the Enzymatic Decontamination Technology (ENDETech) project. This $3.5 million project aimed at developing a commercial technology for the enzymatic degradation of waste pharmaceuticals but did not deliver a commercial product.
In addition to pharmaceuticals, other contaminants (e.g., polycyclic aromatic hydrocarbons) may be present in water. The contaminants may result from incomplete combustion, industrial effluents, and chemical spills such as the Deepwater Horizon incident. Chronic exposure to polycyclic aromatic hydrocarbons has been linked to carcinogenesis and developmental disorders in humans.
Common water treatment techniques (traditionally designed for parasite and microbe removal) such as the activated sludge process are capable of removing some of these contaminants from water streams. However, batch and site disparities in sludge quality are notorious and have led to mixed results in water purification. Furthermore, approaches such as the activated sludge method, although feasible on a plant scale, may not be feasible for deployment to individual users in the field or during site specific catastrophic events.
A more practical alternative would be a non-biologic based alternative that is more reproducible over multiple theaters of deployment. It would be desirable to develop new systems and methods for decontaminating water.